“Stretching 73 miles across some of the most dramatic countryside in England, Hadrian’s Wall dates back to the 1st century AD. Historians still debate the reasons for the construction of the wall. The most popular theory is that on becoming Roman Emperor in 117 AD, Hadrian had the wall built to make his empire more secure. To increase security, forts known as milcastles were placed along the wall at intervals of approximately one Roman mile.”